Measurement of ⁹⁰Sr in Marine Biological Samples

Strontium-90 (⁹⁰Sr) is one of the most hazardous radionuclides, and it contributes to radiation exposure by ingestion. The routine determination of ⁹⁰Sr in marine biological samples is highly desirable given the development of the nuclear power industry. A fast, simple, and low-detection-limit method was developed for the measurement of ⁹⁰Sr in marine biological samples based on determining ⁹⁰Y by means of coprecipitation and solvent extraction with bis-2-ethylhexyl-phosphoric acid (HDEHP) in n-heptane. The interfering ²¹⁰Bi is removed using Bi₂S₃ precipitation. The separation and purification of eight samples per day can be accomplished through this method. The detection limit of ⁹⁰Sr for this method is 0.10 Bq/kg (ash weight). The radiochemical procedure was validated by fitting the decay curve of the sample source and by the determination of ⁹⁰Sr standards.